RUI/Gateway & Modbus®TCP
Configuration & Programming Example
Using KEPServerEX 4.0
Watlow
1241 Bundy Blvd
Winona, MN 55987
Telephone: 507-494-5656
© 2008 Watlow Electric Mfg Co 2 FM 4/08
3. Some notables regarding the graphic above. In the steps that follow we are going to focus on
four of the prompts shown: a. Modbus®Enable (Mb;E) b. Gateway instance (GTW)
c. Gateway enable (du;En) d. Modbus®offset (M;oF)
4. Notice in the graphic in step 2 that the RUI/Gateway has 2 “Com” instances. Com instance 1
will always be Standard Bus and Com instance 2 will always be the user protocol of choice, in
this case, Modbus®TCP. This protocol when ordered also comes standard with EtherNet/IPTM
(Industrial Protocol) as well. When setting the prompts for Com instance 2 you must first
enable Modbus®TCP, EtherNet/IPTM or both. For the purpose of this paper the prompt
displayed as Mb;E will be set to yes (Modbus®TCP enabled). If a step-by-step example is
needed to fully configure the RUI/Gateway refer to step one and download the appropriate
user manual.
5. To implement the network shown in step two the following settings will need to be entered:
Further explanation of these prompts and their associated enumerated values will follow.
6. After completing the configuration as shown above as well as your Com 1 settings for the
Standard Bus side this will complete the RUI/Gateway configuration.
7. Note that KEPServerEX is one of many software packages on the market today that include
the Modbus®TCP driver; this procedure is for KEPServerEX.
8. The following screen shots capture a step-by-step procedure to successfully establish
Communications between the computer (PC) running KEPServerEX and the EZ-ZONE®
RUI/Gateway (Com instance 2) over Modbus®TCP. Once communications are established
over Com instance 2 we will then look further at the KEPServerEX configuration that will
enable communications through the RUI/Gateway to Com instance 1 and the EZ-ZONE®PM
controls (1 - 4) over Standard Bus; thereby establishing a live and active communications link
between dissimilar networks.
Gateway
Instance
Enable
Gateway
Instance
Modbus®
Offset
GTW = 1 Du;En = Yes M;oF = 0
GTW = 2 Du;En = Yes M;oF = 5000
GTW = 3 Du;En = Yes M;oF = *10000
GTW = 4 Du;En = Yes M;oF = *15000
* The RUI allows for a maximum entry of 9999 due to the limitations of the 7 segment display. To enter
an offset > 9999 EZ-ZONE®configurator software must be used.
